Title
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Synthesis, spectral, thermal and thermodynamic studies of oxovanadium(IV) complexes of Schiff bases derived from 3,4-diaminobenzoic acid with salicylaldehyde derivatives
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Abstract
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Synthesis and evaluation of three new oxovanadium(IV) complexes, formed by the interaction of vanadyl
acetylacetonate and the Schiff bases: 3,4-bis((E)-2-hydroxybenzylideneamino)benzoic acid (L1), 3,4-bis-
((E)-2-hydroxy-3-methoxybenzylideneamino)benzoic acid (L2) and 3,4-bis((E)-2,4-dihydroxybenzylideneamino)
benzoic acid (L3) in methanol. The complexes have been characterized and studied by IR spectra,
UV–Vis spectroscopy and thermogravimetry in order to evaluate their thermal stability and thermal
decomposition. According to the results discussed from TG curves, the order of thermal stability for the
complexes is VOL3 > VOL1 > VOL2. Their formation constants (Kf) were obtained by UV–Vis spectroscopic
titration at 15, 25, 35 and 45 C in methanol by SQUAD software. The trend of formation constants of the
complexes as follows: VOL3 > VOL2 > VOL1.
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